There are 4 reasons at once, each of them is enough to prove that it is so necessary to write a check after you call the malloc function. If someone from your team doesn't write the checks, make him read this article.

Null pointer dereference is undefined behavior

Null pointer dereference is a vulnerability

Where are guarantees that dereferencing of exactly a null pointer will occur?

Where are the guarantees that memset fills the memory in a direct order?